Efficiency of Nesidiocoris Tenuis Reuter (Hempitera, Miridae) in Controlling Tuta Absoluta Meyrick (Lepidoptera: Gelechiidae) in Tomato Greenhouses

Tomato leaf miner, Tuta absoluta Meyrick, is a pest which entered Iran in 2010; it was spread rapidly in many areas including Jiroft, in the southern Kerman province. The predatory bug, Nesidiocoris tenuis Reuter (Hempitera, Miridae) is an effective biocontrol agent against T. absoluta in tomato greenhouses. To evaluate the efficiency of N. tenuis in controlling T. absoluta, the predator was released in five treatments including: one pair of adult predator per plant, 6 fourth stage nymphs per plant in the same time with the artificial pest release, one pair of adult predator per plant and 6 fourth stage nymphs per plant one week before artificial pest release and control (no predator). The experiments were done in a completely randomized block design with 3 replications. Evaluation was done on 40 and 70 days after the artificial pest release on 20 plants per plot which had been selected randomly. The results showed that the two treatments of predator release before pest release were significantly better than the others in reducing the number of larvae (5 ± 1.52, 5.1 ± 1.01 on 40th day and 2 ± 0.58, 4 ± 0.58 on 70th day), mines (11.4 ± 2.96, 10.7 ± 2.2 on the 40th day and 4.67 ± 0.67, 6.7 ± 0.88 on 70th day) and the percent of the damaged fruit (4.7 ± 1.45 and 7.3 ± 1.21), as well as increasing the predator established on plants (3.6 ± 0.14, 3.1 ± 0.07 on the 40th day and 5.8 ± 0.2, 4.6 ± 0.24 on the 70th day). Moreover, these two mentioned treatments had no significant difference with the others in regard to the symptoms of N. tenuis damage in plants, especially in the final evaluation; so they could be recommended for use in commercial greenhouses.